Multiple chamber pneumatic tire



l D. o. MccLAY 2,196,814 MULTIPLE CHAMBER PNEUMATICI TIRE Filed Oct. 6, 1938 2 Sheets-Sheet 1 INVENTOR. David O. Mc Clay ATTORNEY April 9, 1940. D. o. MCCLAY 2,196,814

MULTIPLE CHAMBER PNEUMATIC TIRE Filed oct. e', 193s 2 sheetssneer 2 ATTORNEYS Patented A`pr.l9,.1940 :i e 'Y y l rk2,196,814 l MULTIPLE CHAMBER rianniuntlloV TIRE Davia o. .M cciay, seatuawasn. Applioationootober, 193s, serial No. 233,616

11 Claims. (C1..1f.-i2;339)l This invention relates in generalto pneumatic tively, to identify the several inner-tube sections tires, and in particular to improvements in into which each is connected'- y side reinforcements for prolonging the utility Anobject ofthe inventionis toprovide an irn of the tire. proved pneumatic tire havingy a-plurality of sepa- The preferred embodiment of the invention rate airchambers, so arranged and supported 5 vherein disclosed comprises a'tire casing having a by a plurality of interior circumferentially displurality of inwardly projecting and circumferposed annular ribs built into the tire casing, that entially disposed annular reinforcements or ribs in case oneof said chambers blows out or is puncthat are ofthe same material as, and are made tured, the others will continue to support the vev- :integral with, the body-of the tire, the inner edge hicle until repairs can be' made.V y 10 vf portion of leach of said reinforcements being re- Another object is to provide an improved pneuinforced with a suitable iiexiblemetallicv core. matic tirehaving a plurality of air chambers Said 'ribs are adapted tovform a supporting reinwhich may be inflated to different pressures to forcement for the tread and side wall portions enhance the riding qualities of the vehicle and 15 of the tire casing, and their arrangement is such t0 prolong the life of the tire. 15

`4() air-chamber sections, as viewed from thesideof chambers;

that they form a plurality of inter-connected in- Afurther object is to provide 'a pneumatic tire terior chambers, into which preferably correhaving a plurality of independentl air chambers spending physically `inter-connected but pneuin which interior annular ribs made integral with matically independent inner-tube sections are the tire casing are adapted to-support thetire 204 adapted to t f f wall and tread-wall portionsfcooperatively with 20 The medialiy joined aforesaid inner-tube seothev airpressure in said ehambersrthereby eretto' tions .are so disposed as to contact the rounded 1y increasing the Strength end`-pr010nging-the vinner 'edge portions of the aforesaid'ribs,A and the life of the tire. 1 e several tubular sections are constructed to con- Other objects and advantages of my improved formin'shape to the corresponding chambers of tire will be apparent to those skilled in the art 25` y the tire casing in'which they are placed. The from the following detailed description of a prewall of the inner-tube section positioned next ferred form ofthe invention, which consistsgof lto the wheel preferably is heavily reinforced certain parts in cooperative combination, asherewhe-feit contacts the rim of said wheel and the inaiter` described, illustrated inthe accompany- 3obead portions of the tire casing in the usuaI ing drawings .and embraced in the appended '30 Way to prevent chafing the tube. claims. s

The inner-tube structure illustrated is pro- In the draWngS vided with a unitary set of valve stems compris- Figure v1 is atransverse section through the ing three separate and distinct valves, one of tire of `Vmy liVentiOn at the DOSitiOn indicated n Whichleads directly to the large section nextto l by bro-ken line I`l of- Fig, 2, showing the inner- 35 the rim, which I designate as the center airtube structure and casing' fin' placeupon what Q e chamber section of the inner tube. {Ihe other is known in the art as adrop-center wheel rim,4 y"valve 'stems connect to flexible tubes that lead tOgether With thefieXibie tubes leading-imm ther respectively to' the inside and outside smaller l valve-stem unit to the smaller independent airv the car.A l y Fig. 2 is a fragmentary medial'sectional ele- 40' By means of this arrangement it will be geen vation of the aforesaid assembly taken on broken that each independent air chamber may be' ine' `,line 2-2 0f Fig. ltO a Smaller scale; e

fiated to that pressure which Will vhave been Fig. 3 is a transversev sectional elevation ofthe found to be best adapted for the service in which tire casing only of 'theassembly shown in Fis.- 1; 45

,the .tire is employed; and in Case any one of Fig. 4 is a like transverse sectional elevation i the separate air chambers is punctured or should 0f the inner-tube Structure and d1`0D-Center rim y blow out,-theconstruction is such that the reportions of the aforesaid assembly; e

maining air-chamber sections, in combination Fig. 5 is a plan view ofthe `valve-stem unit, j'

owvith. thesupport provided by the reinforcing with a portion of thevinner-tube structure andf` i -thevalve stems inside, outside and center, respec-v structure ytothe same scale'as in Fig. 1, but'taken ribs, are sufficient to'rprevent the complete colflexible connecting tubes in section, taken on lapse lof the'tire until the Vehicle can be brought brokenv line 5-e5 of Fig. 4.; `and y to" a stop and the required repairs can be made. i Fig. 6 isa fragmentary transverse section shovv .i To'facilitate inating the tire I prefer to mark ing the -medial joined portions of the innertube at the position indicated by broken line B-t of Fig. 2.

Like reference numerals are used to indicate like parts throughout the drawings, wherein I indicates the casing as a whole of the tire embodying my improved construction. Referring to Fig. 3, it will be seen that said tire casing comprises the usual reinforced beads indicated at 8 and 8', with which are incorporated the usual side wall construction 9, breakerstrip Ill, and tread II.

In addition to said usual elements of construction, I add an inwardly projecting and circumferentially disposed central annular rib element i2 having a bulbous inner edge portion Ita, prefer ably provided with a medial flexible metallic reinforcing ring I3. Said metallic reinforcing ring rmay be a continuous chain, the links of which are clearly shown in the drawings'.

Projecting inwardly from the respective side walls of the casing are a pair of similar annular rib elements I4 and I4 having bulbous edges ida and Ilia', respectively, each of which may be reinforced with a plurality of medially disposed steel strands I5, each of which is composed of a large number of twisted high-tensile-strength steel wires of small diameter to yassure a maximum of strength and a minimum of resistance to iiexure. Portions |217, Mb, andvldb, respectively, of ribs I2, I4, and I4 that connect with the inner face and side wall portions of the tire casing, preferably are built into said wall portions at the time the tire is made, thereby making them integral with the tire casing itself, as will be apparent to those skilled in the art of tire manufacture. It is important that the interior surfaces of interconnected chambers O, I, and C of the tire casing be smooth with well rounded corners, and they preferably are provided to tlfrs end with a cord fabric lining which is continuous from bead portion 8 on one side of said casing including projections I4, I2, and I4', respectively, to the other lixad portion 8 thereof, as indicated by numeral The inner-tube structure as a whole, hereinafter referred to also as the inner tube, is indicated by the numeral I'I, and the wheel rim by the numeral I8. Referringto Fig. 4, it will be seen that the Walls of the inner tube are shaped to conform to the interior surfaces of the tire casing illustrated in Fig. 3. It will be apparent that tubular portion I'Ia of the inner tube will t readily within chamber I of the tire casing, and that likewise tubular portion IIb of the inner tube will t within chamber O of said casing, the balance of the interior of which is lled by tubular portion I'Ic of said inner tube, preferably reinforced heavily where it contacts beads 8 and 8 and the drop-center portion of the wheel rim, as indicated at I'Id. The aforesaid tubular portions of the inner tube may be joined together by reinforced medial annular portions i9 and IB', which preferably are shaped to conform to bulbous edges I2a, Ilia, and lila. of ribs I2, I4, and I4', respectively, as shown clearly in Figs. 1, 4, and 6.

Valve-stem unit 20 maybe vulcanized to the wall of the inner tube in the usual manner. In Figs. 4 and 5 it will be seen that center valve stem 26o connects directly with chamber C of the inner tube, and that valve stems 26a and 23h are connected by means of flexible tubing elements Ela and 2Ibwith chambers O and I', re-

l' spectively, of the inner tube. It will beapparent that this provides a separate valve stem connection for each of the three separate and independent air chambers of the inner tube, and

that each of said chambers, if desired, may be maintained at a different air pressure. As a rule,

however, I nd that it is desirable to keep the With the tire casing and inner tube thus as sembled, they then may be installed on the dropcenter rim portion of the wheel in the usual man ner, after 'which separate compartments O', I',

and C may be inflated to the, desired pressurelbyr applying an air hose connection to valve stem terminals 2da, 20h, and 20c, respectively, in the usual way. When inflating the tire it is desirable, however, that the three compartments have their pressures increased more or less simultaneously; For example, in order to assure the proper engagement of bulbous edges IM, Ita, and Ma of the interior ribs with medial portions Ill andldf of the inner tube, I prefer rst to increase the; Y pressure invchambers O and I by several alter,-

nate applications of the air hose connection to approximately one-half their respective desired pressures, after which the pressure may be yin# creased in chamber c to a like amount. said chamber then is further inflated in turn in steps of about 25% of the increase in pressure desired until the nal pressure is had chamber.

After the tire is thus assembled and inflated, the relation between the several partsis killustrated clearly in Fig. 1, wherein it will be seen that the inner-tube portions are expanded snugly inti contact with the inner Walls of the several chambers into which the interior of thetire cas ing is divided by interior ribs I2, It, and Iii', Attention isr directed particularly to the `medial portions I9 and I9' of the inner tube, which will be seen to provide a very substantial, yetl flexible, support for the bulbous edge portions of the nterior` ribs. There is little or no opportunity for chang between the said medialv portions ofthe inner tube and said bulbous edge portions, because the severalportions of the inner tube are contact with said edge portions, and because both Each in each y the inner-tube and interior-rib portions are'con-A structed of resilient materials, which permit their moving together as the load isshifted from one part to another of the tread of the rolling tire.

It will be apparent to those skilled in the art that I thus provide three separate and distinct compartments which may be inflated to considerably different pressures, if the operating condi'- tions of the tire indicate this to be desirable, For example, when the vehicle is lightly .loaded it sometimes is desirable to reduce the air pressure in compartments O and I', thereby increasing the support of the treadportion of the tire carried by the tread portion of the tire, it follows that this will result in forcing `a section `of annular rib I2 and its appended parts inwardly usl air pressure in chamber C.

against the medial portions of the inner tube, which in turn transmit the 4forces thus produced Vto bulbous edges Ida andl Ma' of ribs I4 and I4',

respectively, which in turn `are supported by the air pressure in compartment C of the inner tube. As the result of this construction, a comparatively small air pressure in compartments O' and I' isl sufficient to support comparatively heavy loads, as Will be clear from the following explanation:

Interior annular rib i2 and itsappended parts in cooperative combination with the tread portion of the tire, constitute what may be considered as a exible beam, resiliently supported throughl in combination with Fig. l.

The substantially horizontally disposed top wall of the large portion of the inner tube in contact with ribs Ii' and I 4' is forced outwardly by the As said air pressure urges bulbous portions Ida and Ma' outwardly, it will be seen that they in turn transmit the force thus exerted through medialv portions i9 and I9' of the inner tube to bulbous edge portion I2a of rib I2, which in turn supports the medial portion of the tread wall that supports the lload. The arrangement is such that medial portions I9 and I9 of the inner tube are so rmly gripped between said bulbous portions that they are prevented from slipping relative thereto, and the air pressure in chamber C is thereby made effective in supporting the load carried by the tire, under extreme conditions, without any assistance from the usual air pressure in compartments O and I' of the inner tube. Reinforcing rings I3 and I5 prevent the inner edge portions or" their respective ribs from distorting or stretching seriously under abnormal operating conditions.

`From the foregoing it follows that-with the tire inflated as normally required for satisfactory operation, in case either compartment O or com-'- -the pressure in compartment C' is made available automatically through the cooperation of the coacting parts to continue to supportthe load,

thereby enabling the driver to continue to his Adestination at perhaps reduced speed, or in any event -to bring the vehicle to a stop without accident,`which so often is the result of a puncture or blow-out when tires of standard construction are employed.

It will be understood, of course, that the tire is adapted to carry its maximum load when all three compartments of the innertube are iniiated to4 their respective optimum pressures. Because of.-

and when inflation is properly maintained, the

life of the tire is greatly increased'.

Where the vehicle is required to traverse rough roads, it is desirable to reduce the pressure in Vchambers O and I', as compared to the pressure employed in chamber C', thereby enhancing the riding qualities vof the vehicle and prolonging the life of both the tire and the vheicle itself.

Blow-outs when traveling at a high rate of speed are extremely dangerous. When mytire is employed the blow-out of the air in any particular chamber through the corresponding casing wall of the tire, while serious, is decidedly less so than when such an accident occurs with the ordinary tire, for the reason that, inv addition to a pluralityof pneumatic chambers, I employ a tire casing having greatinherent structural strength that serves as a substantial support until the vehicle can be brought to a stop. i' y -It will be apparent to those skilled in the art,

- that the essential coacting elements of my in- Vention may be combined in various other equivalent forms and, proportions Without departing from lthe purpose and intent of the invention within the scope of the appended' claims. i

Having described a preferred form of my in-` vention, what I claim as new and desire to protect by Letters Patent is: i

ljln a pneumatic 'tire of the `class described, the. combination of a tire casing divided into a plurality of inter-connected annular interior compartments by aplurality-of inwardly projecting and circinnferentially disposed annular ribs made integral with the wall portionsof said casing, each said rib comprising a bulbous edge portion, .and an inner-tube structure comprising physically connected but pneumatically independent annular tubular portions adaptedto t within the interiorcompartments of said tire casing with the means used for physically connecty ing said tubular sections disposed intermediate of the adjacent edges of said inwardly projecting 2. In a pneumatic tire'of the class described, the'combination of a tire casing divided into a plurality of inter-connected annular 'interior compartments by a plurality of inwardly projecting and circumferentially disposed annular ribs lng,

each said rib comprising a bulbous edge portion, a continuous `iabric'lining for said inter-v connected compartments, 4and "an inner-tube structure comprising' physically connected but pneumatically independent annular tubular portions adapted to fit within the interior compartments of said tire casing with the means used for Iphysically connecting said tubular sections disposed intermediatefof the adjacent edges oi said-inwardly projecting ribs.

" 3. In a pneumatic tire of theA class described,

the combination of a tire casingdivided finto a plurality 'of inter-connected annular Iinterior compartment-s by a corresponding number of inwardly projecting'and circumferentially disposed annular ribs 4made" integral with thewaltpcrtions of, said casinggeach said rib comprising a bulbousjedge portion, an' inner-tube structure comprising `physically connected butj pneumaticallyl independent annular tubular adaptedto iit within' the interior compartments of said tire casing with themeans used for physicallyponnecting said tubular sections disposed "intermediate oftheadjacent edges of said inwardly projecting ribs, and valve vstern means connectedfwith 'each said pneumatically independent tubular-portion of said inner-tube structure. l v f 4. In a 'pneumatic tire of the class described, the combination of a tire casing` having aplurality of. inwardly projecting and circumferentially disposed v'annular ribs adapted to divide the Vinterior of said casingA into a plurality of inter-- connected charr'lbers, each of said ribs having a bulbous inner edge portion in which is disposed portions l a ringv of flexible metallic reinforcement; and a like plurality of inner-tube means comprising pneumatically independent annular sections adapted to fit within and to be supported by the walls comprising the respective said chambers oi said tire casing.

5. In a pneumatic tire of the class described, the combination of a tire casing comp-rising three inwardly projecting land circumferentially disposed annular ribs that kare composed-of the same material and are made integral with the wall portions of said tire casing, exible metallic core means for reinforcing the' interior edge portion of `each of said ribs, said ribs being so proportioned and so disposed within the tire that they formthree inter-connected chambers, an inner-tube structure comprising'three physically inter-connected but pneumatically independent annular portions each adapted to t within and ll a corresponding said chamber of said tire casing when inflated, said inner-tube structure comprising also a medial construction adapted to engage with the interior edge portion of said ribs, vand. valve stem means connected with each pneumatically separate portion of said innertube structure.

6. In a pneumatic tire of the class described, the combination of a tire casing, a pair of inwardly projecting Aand substantially axially disposed annular ribs composed of the same material as said casing and made integral with the respectively opposite side wall portions thereof, a substantially radiallydisposed inwardly projecting annular rib made integral with the treadwall portion of said tire casing and composed or like material, the inner edge portions of said axially and radially disposed ribs being adjacent to but not touching each other, and an innertube structure shaped to conform to the respective chamber portions into which the interior of said tire casing is divided by the aforesaid ribs,

said inner-tube structure comprising a plurality of medial portions adapted to engage with the adjacent interioredge portions of said ribs and dividing said `inner tube into three physically connected but pneumatically independent air chambers that lit within and are supported by said ribs and the walls of said tire casing.

7. In a pneumatic tire-of the class described,`

the combination of a tire casing comprising a radially disposed annular rib composed of the same material and made integral with the treadwall portion of said casing and comprising also a pair of substantially axially disposed circumferential interior ribs that likewise are of the same material as the body of saidcasing and made integral with the respective side-wall portions thereof, thereby dividing-the interior of said casing into a pair of small outer annular chambers medially inter-connected with a large inner annular chamber, exible metallic means for reinforcing the interior edge portions of eachof said ribs, an inner-tube structure comprising two small outer and one large inner annular sections adapted to fit within the corresponding annular chambers of said tire casing, said annular sections being physically connected by a medial portion adapted to iit between the inner edge portions oi said ribs, and separate valve-stem means connected pneumatically with each of the aforesaid sections of said inner-tube structure.

8. In a pneumatic tire of the class described, the combination of a tire casing comprising a substantially radially disposed interior annular rib made integral with the tread-wall portion of said tire casina pair of inwardly projecting and circumferentially disposed interior ribs made integral with the respective side wall portions of said tire casing and each having a bulbous inner edge portion provided with a medially disposed spective side wall portions of said tire casing, a

substantially radially disposed annular interior rib made integral with the tread-wall portion of said casing and comprising a bulbous inner edge reinforced with a flexible metallic ring `disposed medially of said bulbous portion, the interior of said casing being divided by said ribs into a plurality of inter-connected annular chamberspand an inner-tube structure having physically connected but pneumatically independent annular tubular portions adapted to t within the corresponding said chambers of said tire casing, and means for iniiating each of said pneumatically independent inner-tube portions.

10. In a pneumatic tire of the class described, the combination of a tire casing comprising an interior annular rib made integral with the treadwall portion thereof and having a bulbous inner edge with which is incorporated a ring of flexible metallic reinforcement, a pair of substantially axially disposed circumferential interior annular ribs made integral with the respective side wall portions of said tire casing each having a bulbous inner edge reinforced with a flexible metallic ring, the interior of said tire casing being divided by said ribs into a pair of outer chambers adjacent the tread portion of said tire casing and inter-connected with a third inner chamber bounded by the side walls of said casing and said horizontally disposed ribs, and an inner-tube structure comprising a pair of tubular portions adapted to lit within the corresponding said pair of outer chambers of the tire casing and having a third tubular portion adapted to fit within the said third inner chamber of the tire casing said tubular portions being physically connected but pneumatically independent, and valveA stem means connected pneumatically with each of said tubular portions of said inner tube.

1l. In a pneumatic tire of the class described, the combination of a tire casing comprisingsub- 'stantially radially disposed circumferential an'- nular ribs on the interior of said casing and anguiarly converging, the extremities of said ribs being separated by a predetermined space, an inner tube structure divided into three physically connected annular sections adapted to t within the casing and having a wall portion extending between the saidA extremities of said ribs, the spacing of said extremities being just suicient to enable the inter-positioning of the said wall of said inner tube to lend support to the casing when the casing is under load.

` DAVID O. MCCLAY. 

